Syrian refugee Mahmoud, in the underground shelter where he lives with his family in El Akbiya, Lebanon. UNHCR/S.Baldwin

As the Syrian conflict enters its fourth year, the absolute impunity that pervades the conflict is "absolutely unacceptable", according to the Chair of a panel of UN investigators.

Speaking to the press in Geneva on Wednesday, Mr. Paulo Sérgio Pinheiro, Chair of the UN Commission of Inquiry on Syria, said the leadership of each party to the conflict must be held responsible for the violations of its members.

The Commission, which began documenting violations of international law inside Syria in August 2011, has, presented its 7th report to the Human Rights Council.

Mr. Pinheiro shared with Patrick Maigua the latest details in the UN investigation.